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warning Honeywell

Error Code Code 3

Low battery — the backup battery voltage is below acceptable operating levels.

? What Causes This

Aged backup battery, battery not fully charged, or prolonged power loss.

✓ How to Fix It

  1. Restore AC power to allow the battery to recharge.
  2. If the issue persists, replace the backup battery with a new one.
  3. Ensure the battery is installed with correct polarity.

This error code appears in:

Honeywell Vista-20P Security Panel